By now you’ve probably seen the video of a whitetail doe eating and inhaling lengthwise a 2-foot-long snake. The video, taken by Trey Reinhart with his phone while driving along a road in Texas, has gone viral on Twitter with more than 18 million views.

Wait, aren’t deer herbivore? Plant-eaters?

Yes, and while it’s rare, a deer will sometimes eat animals or animal matter that it runs across. Most documented cases of carnivorous meals have been deer eating the eggs from a bird’s ground nest. Deer have also been know to eat tiny songbird chicks. A few years back, a photo of a deer standing in a creek with a fish in its mouth went viral.

I read where some researchers believe deer may eat eggs, birds, etc. to fuel growth spurts, maintain antler growth or even to safeguard themselves against lean times and habitat change, though this seems suspect to me.

The best and most insightful explanation for why a deer would eat a snake comes from a post on Twitter by my friend Lindsay Thomas of the National Deer Association. Keep in mind that the deer-snake video was filmed in the early June fawning period. Lindsay posted:

“I know this: A doe eats her own afterbirth, likely for nutrition and as anti-predator cleanup. I bet this is an instinctual reaction to similar stimuli (blood/organs) at the right time of year.”